Traditional L.A. Unified schools may have to give up computer labs, parent centers and other rooms to charters under a court order.

Los Angeles school officials are fighting a court order, which took effect Wednesday, that would set aside more classroom seats for charter schools — even if that means traditional schools will lose space for parent centers, computer labs, academic intervention and other services.

Under state law, school districts must offer space to charters that is "reasonably equivalent" to that provided for students in traditional schools. Charters are independently run and are exempt from union contracts and many rules that apply to regular campuses.

L.A. Superior Court Judge Terry A. Green required the school district to make new offers based on a different formula than one it had been using.

Charter advocates see the ruling as ensuring long-overdue compliance with the law — with the potential to provide huge cost savings as well as hard-to-find, quality classrooms.

Locating and paying for classroom space is "one of the largest burdens for charter schools throughout California," said attorney Ricardo Soto, who represents the California Charter Schools Assn., which sued the Los Angeles Unified School District. "Charter schools are growing. Their enrollments are growing. We were very glad that the judge found in our favor."

L.A. Unified officials predicted severe consequences in the years to come. The school system has more independent charters, 186, than any other in the U.S., comprising 14% of total enrollment — more than 93,000 students.

"The district will be forced to cut the vast majority, if not all, intervention and enrichment spaces as well as displace children from their neighborhood schools," attorney David Huff said.

For next fall, the hardships would affect just a handful of traditional campuses — because only five charter schools have said they want to consider new, expanded offers right away.

On Tuesday, the district asked the court to reconsider its decision. The school system is also preparing an appeal.

At issue is how to determine the number of classrooms provided to charters. The district, for example, allots its high school space based on 30 students per classroom; it did the same for charters. Under that formula, the school district provided a seat for every eligible charter student whose school applied for space — a vast improvement in district offers compared with past years.

But the charter association said the district also should factor in rooms not being used for regular classes, such as those for small numbers of severely disabled students, parent centers and computer labs.

Charters would receive more space under that calculation, the association said.

The association suspects that the district is using its formula to conceal under-utilized rooms that should be available.

In court documents, the association said that the district has crowded classrooms partly because of union contracts and how it allocates resources. Charters, the association asserted, should not be forced to have large classes just because the district has them.

The fight over classroom space has persisted for years. Most charters have had to find or build their own campuses. Many have also complained that district offers have been unacceptable.

Groups from neighborhood schools have often protested against charters sharing their campuses, but such arrangements also have proved manageable.

The association and L.A. Unified reached a settlement in 2008 over access to campuses. But charter advocates returned to court to enforce the agreement, most recently in May, alleging that L.A. Unified was failing to comply with legal obligations.